The present invention relates to apparatus including hydrocyclone type clarifiers for removing contaminants from a liquid. More particularly, the invention relates to improvements for minimizing the tendency of a hydrocyclone clarifier to become clogged with foreign matter, and to liquid purification systems incorporating such improved clarifiers.
Liquids used as coolants and/or lubricants in many industrial processes are subject to contamination during use which may render the liquid unsuitable for recirculation and repeated use in the process. For example, many metal working processes are cooled and lubricated by flooding the work area with an appropriate liquid. Fine metal particles and other contaminants are carried away with the liquids, which requires removal of the contaminants to a degree sufficient to allow recirculation if the same liquid is to be continuously recycled through the system.
Various purification systems employ holding tanks wherein the contaminated liquid is allowed to stand for a sufficient time for the denser contaminants to settle to the bottom by gravity. Drag conveyors are frequently provided to remove the settled contaminants from the bottom of the tank. In some processes, additional apparatus has been employed to purify the liquid to a greater extent than normally attained only in settling tanks, and to reduce the necessary retention time of the liquid in the tank, thus reducing the required tank capacity. Such manufacturing processes commonly include rolling or drawing of metal wire through dies to reduce or otherwise alter its cross section.
Apparatus generally known as a hydrocyclone clarifier is conventionally used to supplement the liquid purification process. After some degree of contaminant removal by gravity settling, the liquid is pumped through a hydrocyclone which operates generally on the principle of centrifugal force to remove a greater degree of contaminants. A major difficulty, however, with the use of such apparatus is the tendency of relatively constricted nozzles in the contaminated liquid return line to become clogged with foreign matter such as small pieces of cloth, paper and cigarette butts or filter tips.
It is a principal object of the present invention to provide hydrocyclone-type liquid clarification apparatus having a highly reduced tendency to become clogged, as compared to prior art apparatus of the same type.
A further object is to provide a hydrocyclone clarifier which automatically purges itself of impurities.
Still another object is to provide hydrocyclone liquid clarification apparatus automatically responsive either to a predetermined time lapse or to a drop in flow due to clogging to flush out foreign matter or accumulated contaminants.
A still further object is to provide a purification system for industrial process liquids including holding tanks and improved hydrocyclone clarifiers in a liquid recirculation path.
Other objects will in part be obvious and will in part appear hereinafter.